The invention relates to perforating blades used in high speed web cutting apparatus for the transverse perforating of a web such as the apparatus described in U.S. Pat. No. 2,870,840. Prior art perforating blades such as those disclosed in U.S. Pat. No. 3,190,163 are constructed of standard sheet steel stock, and the blades are ground to certain thicknesses and heights within specified tolerances to provide the desired blade extension. The grinding of the thickness of large flat surfaces of the blades to meet the customer's specifications and tolerances results in considerable expense in manufacturing the blades. The blades are typically ground to one of three thicknesses: 0.032 inch; 0.040 inch; and 0.047 inch. The following blade heights are in common usage within the industry: 0.875 inch; 0.906 inch; 0.925 inch; and 1.000 inch. Operators of this perforating apparatus standardize on a height for their particular equipment (for instance 0.875 inch) and then vary the thickness between the three commonly available sizes according to the individual preference of the operator of this perforating apparatus.